现行义务教育课程北师大版八年级下册实验教材,在“探索三角形相似的条件”一节内容的编排上与过去依据《大纲》编写的教材比较,删去了平行线等分线段定理及推论1、推论2;删去了由该定理衍生的平行线分线段成比例定理(及推论)、三角形一边平行线的性质定理、三角形一边平行线的判定定理、三角形一边平行线的性质定理的扩充命题,共八个定理.应 The current compulsory education curriculum Beijing Normal University version of the eighth grade experimental teaching materials, in the “exploration of similar conditions of triangles ” section of the contents of the arrangement with the past based on the “outline” prepared by the text, the deletion of the parallel bisectors Theorem and Corollary 1, Corollary 2; Remove the proportional theorem (and inference) of the parallel line subdivision derived from this theorem, the theorem of parallelism of one side of triangle, the theorem of determination of parallelism of side of triangle, the parallelism of side of triangle Theorem expansion of the proposition, a total of eight theorems